Irrigation devices are in common use in a variety of non-surgical environments, such as nursing homes and other long-term care facilities, where they are used to treat bed sores and other injuries that are accessible externally about a patient. These devices generally comprise an irrigation handpiece and accompanying irrigation tip that direct irrigation liquid from an irrigation source to an irrigation site. Effective treatment often requires that the injured site be irrigated several times.
Conventional irrigation and suction devices have a combination suction and irrigation tip that can be detachably connected to a handpiece having both irrigation and suction lumens. The free end of the tip has a conical splash shield that, during use, is pressed against and about the irrigated region to confine irrigation liquid (e.g., saline) to that region. A typical tip is shown in U.S. Pat. No. 4,692,140 (Olson). The Olson tip has an outer (suction) tube, an inner (irrigation) tube coaxially aligned with the suction tube, and a web (referred to as "pegs" in Olson) that supports the distal end of the irrigation tube within the suction tube. The annular space between the tubes provides a suction pathway for biological debris aspirated from the irrigation site. Aspirated biological debris is drawn through the suction pathway to the suction lumen in the handpiece, from which it flows through a connecting tube to a debris collection chamber.
One problem with such devices is that the biological debris ingested into the handpiece suction lumen (from the irrigation site) may contain infectious bacteria that could contaminate the handpiece. The handpiece can thus become septic and may create an undesirable risk of reinfection to the patient if it is reused. Accordingly, although irrigation handpieces with detachable tips are available, there has been a resistance to their use because the handpieces are relatively expensive and can only be used once. The preferred treatment is to to bathe the patient in a warm whirlpool bath instead of locally irrigating the injury with an irrigation handpiece and tip. This alternative treatment method is inefficient, however, since it is time consuming and treats both injured and uninjured parts of the patient's body.
Another difficulty with the foregoing coaxial tip is that the suction pathway can clog easily with aspirated biological debris because it has a relatively small cross-sectional dimension. The web also appears to further obstruct debris drawn toward the annular suction pathway since it partially covers the open distal end of the pathway.
A flexible splash shield that is permanently fastened to the distal end of the outer suction tube also presents problems. More particularly, when the irrigation tip must be positioned very close to the irrigation site, it may be necessary to cut off the end of the shield along one of several circumferential ring guides. In addition to being time consuming and cumbersome, the structure of the tip is permanently altered. A new tip must be used to irrigate a larger local injury site.
In addition, it is common during use for irrigation fluid and biological debris to escape from the splash shield because, for example, the irrigation surface may not be smooth or the attendant may inadvertently move the handpiece while irrigating. This can cause the debris and irrigation liquid to splash onto the handpiece and/or attendant, consequently contaminating the handpiece and exposing the attendant to infection.
It therefore is among the general objects of the invention to provide an improved suction/irrigation tip that avoids contamination of the handpiece.